3 * Copyright (c) 2005 Konstantin Shishkov
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include "libavutil/intreadwrite.h"
28 * Westwood SNDx codecs.
30 * Reference documents about VQA format and its audio codecs
32 * http://www.multimedia.cx
35 static const int8_t ws_adpcm_2bit[] = { -2, -1, 0, 1};
36 static const int8_t ws_adpcm_4bit[] = {
37 -9, -8, -6, -5, -4, -3, -2, -1,
38 0, 1, 2, 3, 4, 5, 6, 8 };
40 #define CLIP8(a) if(a>127)a=127;if(a<-128)a=-128;
42 static av_cold int ws_snd_decode_init(AVCodecContext * avctx)
44 // WSSNDContext *c = avctx->priv_data;
46 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
50 static int ws_snd_decode_frame(AVCodecContext *avctx,
51 void *data, int *data_size,
54 const uint8_t *buf = avpkt->data;
55 int buf_size = avpkt->size;
56 // WSSNDContext *c = avctx->priv_data;
58 int in_size, out_size;
61 short *samples = data;
66 out_size = AV_RL16(&buf[0]);
67 *data_size = out_size * 2;
68 in_size = AV_RL16(&buf[2]);
71 if (out_size > *data_size) {
72 av_log(avctx, AV_LOG_ERROR, "Frame is too large to fit in buffer\n");
75 if (in_size > buf_size) {
76 av_log(avctx, AV_LOG_ERROR, "Frame data is larger than input buffer\n");
79 if (in_size == out_size) {
80 for (i = 0; i < out_size; i++)
81 *samples++ = (*buf++ - 0x80) << 8;
85 while (out_size > 0) {
89 count = (*buf) & 0x3F;
92 case 0: /* ADPCM 2-bit */
93 for (count++; count > 0; count--) {
95 sample += ws_adpcm_2bit[code & 0x3];
97 *samples++ = sample << 8;
98 sample += ws_adpcm_2bit[(code >> 2) & 0x3];
100 *samples++ = sample << 8;
101 sample += ws_adpcm_2bit[(code >> 4) & 0x3];
103 *samples++ = sample << 8;
104 sample += ws_adpcm_2bit[(code >> 6) & 0x3];
106 *samples++ = sample << 8;
110 case 1: /* ADPCM 4-bit */
111 for (count++; count > 0; count--) {
113 sample += ws_adpcm_4bit[code & 0xF];
115 *samples++ = sample << 8;
116 sample += ws_adpcm_4bit[code >> 4];
118 *samples++ = sample << 8;
122 case 2: /* no compression */
123 if (count & 0x20) { /* big delta */
128 *samples++ = sample << 8;
131 for (count++; count > 0; count--) {
132 *samples++ = (*buf++ - 0x80) << 8;
135 sample = buf[-1] - 0x80;
139 for(count++; count > 0; count--) {
140 *samples++ = sample << 8;
149 AVCodec ff_ws_snd1_decoder = {
152 CODEC_ID_WESTWOOD_SND1,
158 .long_name = NULL_IF_CONFIG_SMALL("Westwood Audio (SND1)"),